One major problem of multimedia communication is the large variation in the data amount of the transmitted audio and visual information. These discrepancies occur because visual and verbal information are typically correlated in an information exchange event. As a result, high data amount of simultaneous audio and visual information tend to exceed the transmission capacities of the communication infrastructure. For example, in a public switched telephone network (PSTN), a signal distributed between a number of users can carry only a certain amount of information within a given time period. The transmission of visual and verbal information therefore needs to be buffered to allow the transmission of more sophisticated visual information.
The buffering of the information is typically accomplished by independently saving audio information and/or video information. This buffering is accomplished temporally and/or permanently, at the location where the information is created and/or at a remote location. Subsequently, the correlated information is transmitted chronologically with a certain user definable parameter.
U.S. Pat. No. 4,656,654, issued to Dumas, discloses a PSTN-based computer-assisted graphic teleconferencing method and apparatus. In Dumas, graphics and voice can only be communicated alternately. Thus, with Dumas, it is not possible to simultaneously distribute a sketching activity with the contemporaneous explanatory verbal information. In addition, Dumas's invention is embodied in a PSTN-based network and not a distributed computer network such as the Internet.
U.S. Pat. No. 5,832,065, issued to Bannister et al., discloses a PSTN-based synchronous voice/data message system that allows the exchange of audio-graphic messages between specific portable communication devices via a PSTN. More specifically, Bannister et al., discloses how simultaneously generated voice and graphical information can be transmitted over separate voice and data links and synchronized at a recipient's respective voice apparatus and data apparatus. Bannister et al. suggest that a user may wish to develop a sketch or drawing while discussing a mater with a party receiving a phone call.
However, Bannister et al.'s message system neither recognizes nor captures drawing movements of a sketching activity. It is the result of the sketch or drawing activity that is being indiscriminately transmitted as a whole. Information related to the content and/or context of the sketching or drawing activity is ignored. The drawing movements are not captured or utilized.
On the other hand, Bannister et al.'s message system provides a replay function to display the content creation process of the graphical information together with the corresponding voice information based on a time stamping approach. In addition, the message system simultaneously replays the correlated verbal information. The chronological voice and data/graphics can be replayed at different speeds.
Unfortunately, Bannister et al.'s message system is unidirectional and chronological. It does not provide contextual information of a chronologically retrieved message. A user cannot selectively access segments of the chronologically retrieved message. Nor can the user interactively access and select any voice or graphic segment thereof and replay from that segment and on. Moreover, to utilize Bannister et al.'s message system, a user is required to have or have access to a correct or compatible communication device. Otherwise, it is not possible to communicate with another person audio-graphically. Finally, Bannister et al.'s invention is embodied in a PSTN-based point-to-point communication network and requires a centralized switching office or switch center. It is not implemented in a distributed computer network such as the Internet.
The Internet, especially the World Wide Web, has been becoming an increasingly important communication medium in recent years. A number of software products and web pages exist to provide users with possibilities to exchange and collaborate audio/graphical information in substantially real time.
For instance, the RealityWave, Inc. of Cambridge, Mass., USA, provides an Internet-based software platform called VizStream® that allows three-dimensional (3D) graphics to be embedded within a web page accessible by a client user. RealityWave's VizStream® platform enables the access, visualization, and integration of industrial data, including complex 3D models, 2D drawings, and associated information for web-based collaboration and communication. With hierarchical streaming, VizStream® allows 3D graphics and models to be viewed, animated, refined, and configured over a network connection.
Unfortunately, even though RealityWave's software provides an enhanced display technique, it is limited to prepared documents. The client user cannot spontaneously adding sketches or comments to the prepared drawing or document. There is no spontaneity and no bidirectional information exchange of information. Further, only 3D models are displayed and no additional media information like, for instance, audio, video, and graphics.
RealityWave and other existing web-based services and software platforms restrict the users to use predetermined graphical symbols together with written text. Visual information needs to be manually added. Sophisticated information elements within a single displayed image and/or in a chronological context are not captured. What is more, pertinent corresponding audio and/or video information is neither incorporated nor correlated.
Clearly, there exists a continuing need for an advanced multimedia communication system and method that enables two or more persons to easily and effectively communicate and interact with one another via a distributed computer network in substantially real time without being limited by special or specific equipments.